1.4 - Environmental effects on the body systems

Question 1

Describe the effects of high altitude exposure on performance in aerobic and anaerobic activities

Answer 1

• Decreased pp of O2 at altitude (air thinner)
• increased breathing frequency
• decreased blood/plasma volume
• decreased stroke volume
• decreased maximal cardiac output
• reduced pressure gradient so less oxygen to muscles
• improved anaerobic exercise
• lower performance in aerobic activities

Question 2

Explain what is meant by the term “cardiovascular drift” (4 marks)

Answer 2

Hot climate
- cardiovasular drift is the potential side affect
- increased heart rate at given intensity of sub maximal exercise
- due to water loss there is reduced plasma volume
- reduced stroke volume
- in order to maintain cardiac output heart rate must increase

Question 3

Explain the process of thermoregulation

Answer 3

optimum body temp is 37 degrees C
1- Thermoregulation is the process of maintaining this internal core temp
2- thermo receptors detect change in temperature and relay to brain
3- brain sends nerve impulses to the blood vessels positioned near the surface of the skin (vasodilate) increases blood flow to skin so heat can be lost through sweat (cooling)

Question 4

Explain how a performer might plan to optimise performance in their event which is due to take place in a hot climate (5 marks) - preventative measures

Answer 4

PRE COMP (lots of fluids 2-3l per day)
- 7-14 days acclimatisation at higher temp levels
means that increased blood plasma levels, decrease loss of electrolytes through sweat and decrease HR at all levels of exertion

DURING / POST
- wear suitable clothing
- water spray
- rehydrate
- using cooling aids
- drink lots of fluids